Ringworm causes a circular, scaly rash that typically appears 4 to 14 days after your skin contacts the fungus. Despite the name, no worm is involved. It’s a fungal infection that can show up on nearly any part of your body, and the symptoms look quite different depending on where it takes hold.
The Classic Rash on the Body
The signature ringworm lesion is a raised, scaly ring with a clearing center, which is how the infection got its misleading name. The outer border is slightly elevated and often feels rough or bumpy to the touch, while the skin in the middle can look nearly normal. On lighter skin, the ring tends to appear red. On darker skin, it often looks gray or brown, which can make it harder to spot early.
Mild cases produce a single dry, scaly patch. More severe infections can produce multiple overlapping rings, and the rash may weep or ooze if bacteria have entered the broken skin. Itching ranges from barely noticeable to intense, and some people feel a mild burning sensation around the edges of the ring. The patches can appear anywhere on the trunk, arms, or legs, and they tend to spread outward over days if untreated.
Symptoms on the Scalp
Scalp ringworm is most common in children. It starts as a small, scaly patch that may look like dandruff at first. As the fungus works its way into hair follicles, hairs break off at the surface, leaving short stubble or black dots where the hair snapped. You might notice one or several round bald patches that slowly expand.
In some cases, the immune system mounts an aggressive response to the fungus, creating a kerion: a large, thick, swollen abscess that feels soft or boggy to the touch. A kerion can ooze pus from individual hair follicles, look yellow or crusty on the surface, and cause significant tenderness. Fever and swollen lymph nodes in the neck sometimes accompany it. Without treatment, a kerion can lead to scarring and permanent hair loss in the affected area.
Symptoms on the Feet (Athlete’s Foot)
Ringworm on the feet goes by “athlete’s foot,” but it’s the same group of fungi. It tends to show up in one of three patterns:
- Between the toes: Itchy, peeling, cracked skin in the web spaces, especially between the fourth and fifth toes. This is the most common form.
- Moccasin type: A dry, thick scale that covers the sole and sides of the foot, sometimes extending up the heel. It can look like simple dry skin for months before being recognized as fungal.
- Blistering type: Small to medium fluid-filled blisters, usually along the inner arch of the foot. These can be quite itchy and sometimes painful when they rupture.
Secondary bacterial infection is a real risk with foot ringworm because the cracked, broken skin between toes is constantly in a warm, moist environment. If the area becomes very red, hot, swollen, or painful beyond normal itching, bacteria have likely moved in. The World Health Organization notes that bacterial infection of the feet from ringworm can be very painful and disabling.
Symptoms in the Groin (Jock Itch)
Ringworm in the groin typically starts in the skin crease where the thigh meets the torso, then spreads down the inner thigh and sometimes toward the buttocks. The rash may form a full or partial ring shape with a border of small blisters, and the center tends to clear as the edges advance outward. Depending on your skin color, it can appear red, brown, purple, or gray.
Itching and scaliness are the dominant symptoms. The rash is often worse after sweating or exercise. One detail that helps distinguish jock itch from other groin rashes: the fungus frequently spares the scrotum itself, preferring the surrounding skin folds where moisture collects.
Symptoms in the Nails
Nail ringworm develops slowly and is easy to dismiss early on. It usually begins at the tip or side of a toenail (fingernails are less commonly affected) and works its way toward the base. You may notice your nail turning white, yellow, or brown, or developing chalky, cloudy spots.
Over time, the nail thickens and may become misshapen. Debris builds up underneath, sometimes causing the nail to separate from the nail bed, leaving visible space between the nail and the skin beneath it. Eventually the nail can crack, crumble, or break in one or more spots. Nail infections don’t itch the way skin infections do, but thick, distorted nails can become uncomfortable in shoes and catch on socks.
How Ringworm Looks Different From Eczema
Several skin conditions mimic ringworm, and nummular eczema is the most common impostor. Both produce round, scaly patches that can look strikingly similar. The key visual difference is the border: ringworm tends to have a distinct raised, advancing edge with central clearing, while nummular eczema patches are more uniformly dry and scaly throughout, without that ring-shaped border.
The two also behave differently. Ringworm is contagious and spreads through skin contact, shared towels, or contaminated surfaces. Eczema is an inflammatory condition, not an infection, and can’t be passed to anyone. Eczema also tends to favor the legs, while ringworm can appear virtually anywhere. If you’re unsure which you’re dealing with, a skin scraping examined under a microscope or sent for fungal culture gives a definitive answer.
Signs of a Worsening Infection
Most ringworm stays superficial and responds well to antifungal treatment. But certain changes signal that things have progressed. Spreading redness, warmth, and swelling beyond the original rash border can indicate a secondary bacterial infection, specifically cellulitis or impetigo. Pus, honey-colored crusting over the rash, or increasing pain (rather than just itch) are other red flags.
Scalp infections that develop into kerions, nail infections that distort multiple nails, and foot infections with deep cracking all represent more advanced disease that typically needs oral antifungal treatment rather than a topical cream alone. Ringworm that keeps expanding despite over-the-counter antifungals, or that returns after treatment ends, also warrants a closer look to confirm the diagnosis and rule out resistant strains or a look-alike condition.